Furnace wall construction



May 1945. R. A. FORESMAN FURNACE WALL CONSTRUCTION Filed May "12, 1942 3Sheets-Sheet l INVENTOR WITNESSES:

ROBERT R. Fbnesmnm} BY Qas'z I ATTORNEY May 15, 1945. FORESMAN 2,375,841

FURNACE WALL CONS TRUCTION Filed May 12, 1942 5 Sheets-Sheet 2- is asINVENTOR ROBERT H. Fb'REsMnN- QI'VS.

ATTORNEY May 1945- R. A. FORESMAN 2,375,841

FURNACE WALL CONSTRUCTION Filed May 12, 1942 3 Sheets-Sheet 3 ATTORNEYPatented May 15, 1945 2,375,841 FURNACE WALL CONSTRUCTION Robert A.Foresman, Prospect Park, Pa., assignor to Westinghouse Electric &Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania Application May 12, 1942, Serial No. 442,611

4 Claims.

header with the stoker structure and eliminates the refractory wallheretoforeused for connecting these parts.

Another object of the invention is to provide, in a stoker-firedfurnace, a wall structure contiguous to the upper edge of the gratesurface to which. slag and clinker will not attach themselves to extendoutwardly therefrom over the fuel bed, thereby adversely affectingignition and burning of the fuel.

A further object of the invention is to'provide, in a stoker-firedboiler furnace, a water-cooled front wall movable vertically relative tothe stoker.

Another object of the invention is to provide, in a stoker-firedfurance, a flexible seal between the lower edge of the furnace frontwall and the stcker, whereby the former may move vertically relative tothe latter.

Yet another object of the invention is to provide improved airdistributing box structure for a furnace fired by a multiple retortunderfeed stoker.

These and other objects are effected by the invention as will beapparent from the following description and claims taken in accordancewith the accompanying drawings, forming a part of this application, inwhich:

Fig. 1 is a fragmentary transverse sectional view through the front wallof a Stoker-fired furnace at its point of connection with the 'stoker;

Fig. 2 is a view taken along the line H-II of Fig. 1, looking in thedirection of the arrows; and,

Fig. 3 is a view similar to Fig. 1, but showing a modified construction.

Referring now to the drawings more in detail there is shown, at H), afurnace having a front wall H, the furnace being fired by an underfeedstoker l2 downwardly inclined from the front wall of the furnace towardthe rear wall thereof.

The Stoker includes a plurality of retorts l3 5 having aligned therewithstoker ram boxes l4 including throat members I6 adjacent the upper endsof the retorts and providing for passage of fuel from the hopper H tosaid retortsw Fuel is fed through the throat members It by the usualprimary ram l8, and along the retorts' by the secondary ram structures 19, to overflow laterally onto the rows of tuyere members 29 whichseparate the retorts IS.

The upper or forward end of the stoke-r I2 is supported by the usualstructural members 22, 23, and 24. A special supporting bracket 26 ismounted upon the structural member 24 and serves to support not only theram boxes 54 but also lower and upper sections 21 and 28, respectively,of an air distributing box structure. In addition to being dividedhorizontally into the upper andlower sections 2'! and 28, the airdistributing' box structure is divided vertically at the centerlines ofthe retorts, for ease in manufacture, assembly and replacement. Thelower and upper sections 2? and 28 are provided with inwardly directednose portions 29 and 36, respectively, overlying the upper ends of therows of tuyere members 20 and being open at the bottom to provide apassage 32 for flow of air from beneath the tuyere rows to the interior33 of the air distributing box structure. The reason for forming the airdistributing box structure in lower and upper sections 21 and 28 will beexplained later} The forward or outer wall of the air distributing boxstructure is formed by a flexible wal1 portion 34 secured at its loweredge to the supporting bracket 26 and at its upper edge to a dependingflange 36 carried by a horizontal header 3'! of the furnace front wallH. The flexible wall member 34 is provided intermediate its edges with aU-bend 38 or the equivalent to permit of vertical movement of thefurnace front wal1 I! with respect to the upper end of the stoker, toallow for expansion and contraction of the front wall due to temperaturechanges occurring in the latter. I

The furnace front wall ll includes a plurality of tubes 4|, 42, and 43,extending upwardly from the header 31 to a boiler (not shown). The tubes4| extend vertically along the inner face of the Wall and preferably arecovered at the furnace sides with suitable refractory material 44. Ifdesired, the space between the various tubes may be filled with brickwork 46, although the presence or absence of such brick work isimmaterial to the present invention. Preferably, the refractory material44 is omitted from a portion 41 of each tube 4| to provide for passageof auxiliary air from the air passage 48.

The upper end of the inner or rear wall of the air distributing boxstructure is spaced slightly from the overlying horizontal header 31 toprovide a passage 5| for flow of air from the distributing box to theinterior of the furnace. To provide for uniform flow of air at thispoint regardless of the relative vertical position of the header 3'!with respect to the stoker I2, there is provided a baffle 52 dependingvertically from the header 3'! and disposed in parallel but spacedrelation with respect to the rearward wall of the air distributing boxstructure, thereby providing a passage 53 constituting a continuance ofthe passage 5|. It will be apparent that there is thus provided an exitpassage for air from the air distributing box structure which will be ofconstant cross-sectional area regardless of changes in the dimension ofthe passage 5| resulting from vertical movement of the header.

Because of the presence of the depending baffie 52 it becomes necessary,for the purposes of assembly or disassembly, to form the airdistributing box rear wall structure in upper and lower sections?! and28, as previously described. These sections, in addition to beingbolted, or otherwise secured, to the supporting bracket 26, areinterlocked by a depending lug 55 on the upper section 28 adapted tomate with a corresponding recess 56 formed. in the lower section 21. Inorder to remove the sections 21 and 28 after they have been unboltedfrom the supporting bracket 26, it is only necessary to raise the uppersection 28 sufliciently to permit the depending lug 55 to clear theupper surface of the lower section 21, whereupon the latter may bewithdrawn rearwardly to the interior of the furnace, after which theupper section 28 can be dropped sufficiently to clear the dependingbafile 52.

In Fig. 3, there is illustrated a construction differing from thatillustrated in Figs. 1 and 2 in that the air distributing box is made inunitary sections and serves as a fixed support for the horizontal header31. tributing box structure is supplied to the interior of the furnacethrough spaced discharge openings 16. It will be apparent that in thisarrangement expansion occurring in the furnace front wall I I must takeplace in the upper portion thereof by bends in the tubes where theyenter the furnace boiler, in the conventional manner (not shown).

While the invention has been shown in several forms, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various other changes and modifi- Air from the discationswithout departing from the spirit thereof, and it is desired, therefore,that only such limitations shall be placed thereupon as are specificallyset forth in the appended claims.

What is claimed is:

1. In a boiler furnace fired by a multiple retort underfeed stokerproviding a fuel-supporting surface within the furnace and downwardlyinclined from the front toward the rear of said furnace, a water-cooledfront wall comprising water tubes extending downwardly from a boiler, ahorizonta1 header receiving the lower terminal portions of said watertubes and disposed in close proximity to the upper end of the stoker,air distributing box structure associated with the upper end of thestoker, and means providing a flexible air-tight seal between thehorizontal header and said air distributing box structure whereby theheader and associated water wall structure may move vertically withrespect to the stoker structure 2. In a boiler furnace fired by amultiple retort underfeed stoker providing a fuel-support- ,ing surfaceinclined downwardly from the front toward the rear of the furnace;throat members aligned with the upper ends of the retorts for passage offuel to the latter; a water-cooled front furnace wall comprising watertubes extending downwardly from a boiler and terminating in a horizontalheader; and air distributing box structure associated with the throatmembers and the upper ends of the stoker tuyere rows and comprising arear wall spaced along its upper edge from the horizontol header toprovide a passage for flow of air from the air distributing boxstructure to the interior of the furnace, and a flexible front wall inairtight engagement with the horizontal header and the upper ends of thestoker tuyre row structures, whereby said header and its associated wallstructure may move vertically relative to said upper ends of the stokertuyere row structures.

3 Structure as specified in claim 2, including bafile means carried bythe horizontal header in parallel, spaced overlapping relation to therear wall of.the air distributing box structure with the space betweensaid baflie means and said rear wall constituting a continuation of theair passage, whereby the cross-sectional area of said passage willremain constant during vertical movement of the horizontal header withrespect to the upper ends of the tuyere rows.

4. Structure as specified in claim 2, including baflie means carried bythe horizontal header for directing air flowing from the airdistributing box structure.

ROBERT A. FORESMAN.

